Abstract:Yield condition of sintered powder materials are introduced briefly,the velocity discontinuity law of which in plane strain is deduced and equation of upper bound power for plane strain isderived.The upper bound solution of pressure for sintered powder materials in smooth plate upsetting is derived from the upper bound method,and theoretical calculation is verified by experimentof smooth plate upsetting with rectangular specimen of sintered copper.

Key words: sintered powder material upper bound method plane strain